Verbs of Incomplete Predication

In the example sentences given above the intransitive verbs cried and slept have no objects, but the sentences still make complete sense.

Now consider the examples given below.

The earth is …
Alice seems …
The milk turned …
Honey tastes …

You will have noticed that the sentences given above do not make complete sense because their predicates (is, seems, turned, tastes) are incomplete. Each of these sentences requires a word or words to make the sense complete.

When the adjective round is added to the fragment ‘The earth is’, the sentence becomes meaningful. Similarly the adjective upset turns the fragment ‘Alice seems’ into a meaningful sentence.

Such a verb which requires a word or words to complete the predicate is called a verb of incomplete predication. Examples are: be (is/am/are/were/was), appear, become, look, seem, smell, grow, turn etc.
The word or words required to make the sense complete is called the complement of the verb.

The complements of intransitive verbs can be nouns, pronouns, adjectives, adverbs, participles, prepositional phrases and infinitives.

Alice is my sister. (Here the complement is the noun sister.)
This bag is mine. (Here the complement is the pronoun mine.)
He is nice. (Here the complement is the adjective nice.)
The child fell asleep. (Adverb)
This machine is of no use. (Prepositional phrase)
This house is to let. (Infinitive)
She continued reading. (Present participle)
She seemed distressed. (Past participle)